Recurrent haemolytic uraemic syndrome and acquired hypomorphic variant of the third component of complement

Pediatr Nephrol. 1990 Nov;4(6):597-9. doi: 10.1007/BF00858631.


In a girl with recurrent haemolytic uraemic syndrome (HUS), persistently low serum levels of C3 were found. Analysis of complement phenotype revealed a hypomorphic variant of C3 Fast in the patient (C3fS) and a normal heterozygous pattern in both parents and the brother (C3FS). Other complement aberrations in the patient were: the presence of a null gene for C4A and C4B and low serum levels of factor H. The father also had partial factor H deficiency. It is hypothesized that the hypomorphic C3 variant may predispose to recurrent HUS. In the acquired forms the role of uraemia in alteration of C3F should be considered.

Publication types

  • Case Reports

MeSH terms

  • Complement C3 / genetics*
  • Complement C3b*
  • Complement C3d
  • Complement C4 / genetics
  • Female
  • Hemolytic-Uremic Syndrome / diagnosis
  • Hemolytic-Uremic Syndrome / immunology*
  • Humans
  • Infant
  • Phenotype
  • Recurrence


  • Complement C3
  • Complement C4
  • complement C3f
  • Complement C3b
  • Complement C3d